As well known, turbine bearing housing instrumentation typically includes thermocouples and proximity probes in the region of the thrust and journal bearings for the turbine rotor. During normal operation, both types of instrumentation are used to measure important physical conditions within each bearing housing. Measurement is accomplished with external meters which receive electrical signals from the instrumentation through insulated wires or cables (hereafter referred to as wires or signal-bearing wires). By necessity, the wires pass through each housing at convenient penetration points which are sealed to prevent oil leakage. Externally, the wires are enclosed within a conduit to provide protection from hostile environmental conditions. Internally, the wires are enclosed within guide tubes securely mounted to and within each bearing housing. It is important to enclose the wires within the housing; because undue wire flexing, unless restricted, results in damage to the wires due to whipping or flailing of the wires caused by turbulent oil flow within the housing.
Bearing housings of a turbine rotor typically includes upper and lower housing sections split along a generally horizontal plane such that the upper housing section may be removed for inspection and maintenance of signal-bearing wires and protective guide tubes, associated with the bearings and other parts. Bearing instrumentation are generally located in the lower housing section. When it is desired to retrofit instrumentation components, guide tubes and wires into a bearing housing, general installation of the same has heretofore been possible in the field, or on other occasions in the factory, only after rotor removal and major tear-down of the turbine. It will also be appreciated that, with the upper bearing housing section removed, access to the lower bearing housing section is extremely limited due to the presence of the bearings and the rotor in the lower housing section. Moreover, it is costly and time-consuming to remove the rotor and other parts of the turbine to facilitate access into the lower housing for purposes of installing bearing instrumentation and related material. It will also be appreciated that the lower housing section is closed and generally inaccessible along its sides except for lubrication drain and supply penetration points which open through the end face or bottom of the bearing housing. Thus, limited access to the inside of the lower housing section has prevented ready retrofitting of protective guide tubes for instrumentation signal-bearing wires without major tear-down of the entire turbine and removal of its rotor. Normally, guide tubes are installed upon the initial manufacture of the turbine and general retrofitting heretofore has been considered clearly impractical due to the foregoing shortcomings.